Abstract:

A wind power installation module comprising wind turbines arranged on a
support body, each of the wind turbines comprises a rotor with a certain
number of blades, a stator supporting the rotor in such a way that the
rotor may rotate on the turbine axis for generating electric energy and a
shroud extending circumferentially around the stator and the rotor and
supporting the stator so as to define an air channel of a certain air
channel diameter at an inlet portion of the shroud. The shroud has a
maximum outer diameter such that the air channel diameter is comprised in
the range from 0.82 to 0.9 times the maximum outer diameter. Furthermore,
the shroud has a length in direction of the turbine axis that is
comprised in the range from 0.1 to 0.25 times the outer diameter.

Claims:

1. A wind power installation module, comprising a substantially
streamlined support body, said support body having a substantially
drop-shaped horizontal cross section, said support body comprisinga nose
body having a substantially hemielliptical horizontal cross section and a
tail body located downwind of said nose body, said tail body having a
junction with said nose body, said tail body and said nose body being
arranged substantially flush with one another at said junction, said tail
body tapering in downwind direction in such a way that a contour of said
tail body follows a parabolic course;said wind power installation module
further comprising wind turbines arranged on said support body at said
junction of said nose body and said tail body, each one of said wind
turbines including:a rotor comprising a certain number of blades;a stator
supporting said rotor in such a way that said rotor may rotate on a
turbine axis of the turbine for generating electric energy;a shroud
extending circumferentially around said stator and said rotor, said
shroud supporting said stator so as to define an air channel having a
certain air channel diameter at an inlet portion of said shroud;wherein
said shroud has a maximum outer diameter such that said air channel
diameter is comprised in the range from 0.82 to 0.9 times the maximum
outer diameter, and in that said shroud has a length in direction of said
turbine axis that is comprised in the range from 0.1 to 0.25 times the
maximum outer diameter of said shroud.

2. A wind power installation module as claimed in claim 1, wherein said
blades have a pitch adjustable to wind speed.

3. A wind power installation module as claimed in claim 1, wherein said
stator includes a central nose portion arranged on the turbine axis
upwind of said rotor, said central nose portion being rotationally
symmetrical with respect to said turbine axis, wherein said central nose
portion has the shape of a hemiellipsoid rotationally symmetrical about
said turbine axis.

4. A wind power installation module as claimed in claim 3, wherein said
stator comprises a central tail portion arranged on said turbine axis
downwind of said rotor, said central tail portion including a
substantially rotationally symmetrical tail fairing, said tail fairing
having a diameter substantially equal, at said rotor, to a diameter of
said nose portion, said tail fairing tapering in downwind direction to
said turbine axis so that, in a longitudinal cross section along said
turbine axis, a contour of said tail fairing follows a parabolic course.

5. A wind power installation module according to claim 1, wherein each
wind turbine comprises a protective grid for protection against birds
mounted upwind of the rotor.

6. A wind power installation including a wind power installation module
according to claim 1, wherein said support body is substantially
rotationally symmetrical with respect to a longitudinal support body
axis, wherein said wind turbines are arranged circumferentially around
said support body in a plane perpendicular to said support body axis,
andwherein said support body is rotatably mounted with respect to a
vertical axis.

7. A wind power installation module according to claim 1, wherein said
support body has substantially vertical outer walls, said support body
being substantially symmetrical with respect to a longitudinal vertical
plane, and wherein said wind turbines are arranged on said support body
on both sides thereof with respect to said vertical plane.

8. A wind power installation comprising a plurality of wind power
installation modules according to claim 7 arranged one on top of the
other, said wind power installation modules being rotatably mounted about
said vertical axis.

9. A wind power installation module according to claim 1, wherein said
support body has a substantially semicircular transversal cross section
and is substantially symmetrical with respect to a vertical, longitudinal
plane, and wherein said wind turbines are arranged in a semicircular
configuration on said support body.

10. A wind power installation comprising a wind power installation module
according to claim 9, wherein said turbines are rotatable about a common
vertical axis.

Description:

TECHNICAL FIELD OF THE INVENTION

[0001]The present invention generally relates to wind turbines and wind
power installations, in particular to wind power installations of modular
construction.

BRIEF DISCUSSION OF RELATED ART

[0002]Different types of modular wind power installations are known. CH
668 623 A5 describes a wind power device with a plurality of stages
carrying wind turbines, and wherein each stage can be oriented into the
wind independently from the other stages. SU 1645603 A1 relates to a wind
power installation wherein an arrangement of wind turbines is hanged from
masts. U.S. Pat. No. 5,328,334 discloses a wind power installation,
wherein propellers are mounted in series on a wind line that extends
between posts. JP 04-350369 relates to an airship moored to ground that
carries a plurality of wind turbines. U.S. Pat. No. 4,140,433 discloses
wind-driven turbines and arrangements thereof. DE 39 05 337 A1 discloses
a method for concentrating the wind stream at a wind turbine with a
horizontal axis. WO 2004/099607 discloses a wind turbine a with a rotor,
a stator supporting the rotor and a relatively short diffusing circular
shroud extending circumferentially around the stator and the rotor, the
length of the shroud amounting to about 0.23 times the maximum outer
diameter of the shroud. The shroud defines an air channel having a
certain air channel diameter at an inlet portion of the shroud amounting
to about 0.83 of the maximum outer diameter of the shroud.

[0003]Wind power installations comprising a plurality of wind turbines
currently suffer from different drawbacks. First of all, the efficiency
of the installation may be low because of an adverse interference of
neighbouring wind turbines due to eddies caused by the blades of the wind
turbines. Second, the complexity of the installations makes it difficult
to orient the wind turbines into the wind for optimising the efficiency
of the installation. Third, the efficiency of the installations may be
suboptimal because of to high a starting wind speed, i.e. the minimum
wind speed for the wind turbines to operate. In addition, wind turbines
constitute a serious danger for birds.

BRIEF SUMMARY OF THE INVENTION

[0004]The invention provides an improved wind power installation module
suitable for use in a wind power installation of modular construction.

[0005]The invention concerns wind power installation module comprising a
substantially streamlined support body. The support body has a
substantially drop-shaped horizontal cross section and comprises a nose
body having a substantially hemielliptical horizontal cross section and a
tail body located downwind of the nose body. The tail body has a junction
with the nose body, at which the tail body and the nose body are arranged
substantially flush with one another, and departing from which the tail
body tapers in downwind direction in such a way that a contour of the
tail body follows a parabolic course at least in the horizontal cross
section. The wind power installation module further includes wind
turbines arranged on the support body at the junction of said nose body
and the tail body, each one of said wind turbines including a rotor with
a certain number of blades, a stator supporting the rotor in such a way
that the rotor may rotate on the turbine axis for generating electric
energy and a shroud extending circumferentially around the stator and the
rotor and supporting the stator so as to define an air channel that has a
certain air channel diameter at an inlet portion of the shroud. The
shroud has a maximum outer diameter such that the air channel diameter at
the inlet portion of the shroud is comprised in the range from 0.82 to
0.9 times the maximum outer diameter of the shroud. This choice of
dimensions provides for minimal aerodynamic losses when the air enters
the air channel during operation of the wind turbine. Naturally, this
increases the efficiency of the wind turbine. Furthermore, the shroud has
a length in direction of the turbine axis that is comprised in the range
from 0.1 to 0.25 times the outer diameter. It is worthwhile noting that
in longitudinal direction, i.e. in direction of the turbine axis, the
shroud not necessarily extends along the entire length of the stator. As
will be appreciated, the arrangement of the turbines at the junction of
the nose body and the tail body is advantageous in terms of efficiency
and starting speed. The junction corresponds to the region where the
transversal cross section of the support body is the most important so
that the wind speed is increased in the region of the junction.

[0006]Preferably, the pitch of the blades is dynamically adjustable to
wind speed.

[0007]In the wind turbines, the stator preferably includes a central nose
portion arranged on the turbine axis upwind of the rotor (for the sake of
clarity, the term "nose portion" is used herein for distinction with the
"nose body", which is part of the support body of the module). The
central nose portion is preferably rotationally symmetrical with respect
to the turbine axis and has the shape of a hemiellipsoid that is
rotationally symmetrical about the turbine axis. The diameter of the
central nose portion in direction perpendicular to the turbine axis is
advantageously comprised in the range from 0.4 to 0.6 times the maximum
outer diameter of the shroud, i.e. the air channel diameter, and the
length of the central nose portion in direction of the turbine axis is
advantageously comprised in the range from 0.4 to 0.5 times its diameter
in perpendicular direction.

[0008]Advantageously, the stator comprises a central tail portion arranged
on the turbine axis downwind of the rotor that includes a substantially
rotationally symmetrical tail fairing (for the sake of clarity, the term
"tail fairing" is used herein for distinction with the "tail body", which
is part of the support body of the module). At the rotor, the tail
fairing has a diameter substantially equal to the diameter of the nose
portion. In downwind direction, the tail fairing tapers to the turbine
axis so that, in a longitudinal cross section along the turbine axis, the
contour of the tail fairing follows a parabolic course.

[0009]Most preferably, each one of the wind turbines comprise a protective
grid for protection against birds mounted upwind of the rotor.

[0010]In a further aspect, the invention concerns wind power installations
comprising or consisting of one or more wind power installation modules
as discussed above. According to a preferred embodiment, a wind power
installation module comprises the substantially streamlined support body,
which is rotatably mounted with respect to a vertical axis and supports a
plurality of the above wind turbines. The support body has the
substantially drop-shaped horizontal cross section and is substantially
rotationally symmetrical with respect to a longitudinal support body
axis. The plurality of wind turbines are arranged circumferentially
around the support body in a plane perpendicular to the support body
axis. In addition, the support body comprises a nose body located upwind
of the plane in which the wind turbines are arranged, and a tail body
located downwind of this plane. The nose body has the shape of a
hemiellipsoid rotationally symmetrical about the support body axis. At
the plane of the wind turbines, the tail body is arranged substantially
flush with the nose body, and it tapers in downwind direction to the
support body axis so that, in a longitudinal cross section along the
support body axis, a contour of the tail body follows a parabolic course.

[0011]According to another preferred embodiment, the support body of the
wind power installation module, has the substantially drop-shaped
horizontal cross section and substantially vertical outer walls. The
first wind power installation module is substantially symmetrical with
respect to a longitudinal vertical plane and comprises a nose body of
substantially hemielliptical horizontal cross section and a tail body
located downwind of the nose body. The tail body is arranged
substantially flush with the nose body and tapers in downwind direction
to the longitudinal vertical plane. Wind turbines are arranged on the
first wind power installation module on both sides thereof with respect
to the vertical plane of symmetry. Such modules can be assembled to a
wind power installation with a substantially streamlined support body,
wherein the support body extends substantially along a vertical axis and
comprises a plurality of first wind power installation modules arranged
one on top of the other. In order to achieve good efficiency, the wind
power installation modules are rotatably mounted about the vertical axis.

[0012]According to yet another embodiment, the support body of the wind
power installation module has the substantially drop-shaped horizontal
cross section, a substantially semicircular transversal cross section and
is substantially symmetrical with respect to a vertical, longitudinal
plane. It comprises, furthermore, a rounded nose body and a tail body
located downwind of the nose body. The tail body is arranged
substantially flush with the nose body and tapers in downwind direction.
Wind turbines are arranged in a substantially semicircular configuration
on the second wind power installation module. Preferably, the turbines of
the module are rotatable about a common vertical axis. It should be noted
that the second wind power installation module may be arranged on top of
a series of the previously discussed wind power installation modules as a
terminal module or, alternatively, as a standalone module.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]Preferred embodiments of the invention will now be described, by way
of example, with reference to the accompanying drawings in which:

[0014]FIG. 1 is a longitudinal cross sectional view of a wind turbine;

[0015]FIG. 2 is a transversal cross sectional view of the wind turbine of
FIG. 1;

[0016]FIG. 3 is a horizontal cross sectional view of a first embodiment of
a wind power installation;

[0017]FIG. 4 is a transversal cross sectional view of the wind power
installation of FIG. 3;

[0018]FIG. 5 is a horizontal cross sectional view of a second embodiment
of a wind power installation;

[0019]FIG. 6 is a transversal cross sectional view of the wind power
installation of FIG. 5;

[0020]FIGS. 7a, 7b are side views of a wind power installation similar to
that of FIG. 5

[0021]FIG. 8 is a longitudinal cross sectional view of a third embodiment
of a wind power installation;

[0022]FIG. 9 is a transversal cross sectional view of the wind power
installation of FIG. 8;

[0023]FIGS. 10a, 10b are side views of a variant of the wind power
installation of FIG. 8.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0024]FIGS. 1 and 2 show preferred embodiments of a wind turbine 10 for
use in a wind power installation module according to the present
invention. The wind turbine 10 comprises a stator 14 bearing a rotor 16.
The rotor 16 comprises a certain number of blades 18, whose pitch is
dynamically adjustable to wind speed. The stator 14 comprises a central
portion 20 extending along the turbine axis 22 and stator blades 24,
which extend radially outwardly from the central portion 20 and which are
fixed to a shroud 26. The shroud 26 extends circumferentially around the
rotor 16 and the stator 14. The stator 14 and the shroud 26 define an
annular wind channel.

[0025]The central portion 20 of the stator 14 includes a nose portion 28
arranged upwind of the rotor 16 and a tail portion 30 located downwind of
the rotor 16. The nose portion 28 is rotationally symmetrical with
respect to the turbine axis 22 and has the shape of a hemiellipsoid of
rotation about the turbine axis 22. The tail portion 30 comprises a tail
fairing 30 that is rotationally symmetrical with respect to the turbine
axis 22 and control surfaces 34.

[0026]A protective grid 12 is arranged upwind of the rotor 16, at the
inlet of the annular wind channel to avoid that birds are dragged into
the turbine by the air stream. The turbine 12 can be rotatably arranged
on a mast 36. The protective grid 12 can, for instance, be made of
caproic fibres (i.e. coal-plastic fibres). The mesh size of the grid and
the material are chosen so that the aerodynamic losses are minimised
while offering acceptable protection for birds. Preferably the clear area
of the grid amounts to 96-98% of the cross sectional area of the air
channel, so that the averaged hydraulic losses due to the grid are
comprised in the range from 2-4%.

[0027]During operation of the wind turbine 10, the wind enters the turbine
10 from the side of the nose portion 28. The streamlined nose portion 28
directs the incoming wind away from the turbine axis 22, through the
protective grid 12, into the annular air channel between the central
portion 30 and the shroud 26. The reduction of the cross section
available for the wind causes an increase of the wind speed in the
annular air channel. In case the streamlined stator blades 24 are located
upwind of the rotor blades 18, a preliminary spin is created in the front
of the rotor 16. It should be noted, however, that the streamlined stator
blades may also be arranged downwind of the rotor 16. The rotor 16 which
then transforms the kinetic energy of the wind into mechanical energy of
rotation. The rotor 16 drives a shaft that is coupled with an electric
generator. Having passed the stator blades 24 and the rotor blades 18,
the air leaves the air channel and streams alongside the tail fairing 30
and the control surfaces 34, which turns the turbine 10 upwind.

[0028]The power P of wind having the density p, streaming at wind speed V
through a cross section A is given by:

P = 1 2 ρ AV 3 . ##EQU00001##

The power P1 of an incident airflow streaming through an area of the
diameter D1 is

P 1 = 1 2 ρ π ( D o 2 ) 2 V 1 3 ,
##EQU00002##

where V1, is the speed and p the density of the incoming airflow. The
power P2 of the airflow streaming through the air channel is

P 2 = 1 2 ρ π [ ( D o 2 ) 2 - ( D
i 2 ) 2 ] V 2 3 , ##EQU00003##

[0029]where V2 is the air speed in the air channel, Do is the
outer diameter of the air channel (i.e. the inner diameter of the shroud
26), Di is the inner diameter of the air channel (i.e. the diameter
of the nose portion 28). The ratio P2/P1 depends on the
Do, Di, V1 and V2. It should be noted that V2
depends on the speed of the incoming airflow V1. It has been found
that the ratio P2/P1 is maximum if the ratio Di/Do
lies in the range of 0.4 to 0.6 and if the ratio LN/Di of the
length LN of the nose portion 28 to the diameter Di of the nose
portion lies between 0.4 and 0.5. Choosing the dimensions Di/Do
and LN/Di in the indicated ranges reduces by a factor 2 the
starting wind speed, compared to a conventional wind turbine without a
shroud, from approximately V1=4 m/s down to approximately 2 m/s.

[0030]In a longitudinal cross section of the turbine 10, as shown in FIG.
1, the contour of the tail fairing 2 is described by a parabola

d ( x ) D i = 1 - x 2 L T 2 , ##EQU00004##

where x is the distance from the rotor on the turbine axis, d(x) the
diameter of the tail fairing at the distance x from the rotor, Di
the diameter of the tail fairing at the rotor and LT the length of
the tail fairing. In practice, the length LT may be approximately
equal to Di or comprised in the range from 1 to 2 times Di.

[0031]The length LS of the shroud 26 in the direction of the turbine
axis corresponds to at least to the sum of the lengths of the stator
blades 24 and the rotor blades 18 in the direction of the turbine axis.
Experimental results indicate that an optimum value of the length LS
is preferably comprised in the range from 0.1 to 0.25 times the outer
diameter DS of the shroud 26. Furthermore, the outer diameter
DS is chosen such that the outer air channel diameter Do (i.e.
the inner diameter of the shroud 26) is comprised in the range from 0.82
to 0.9 times the outer diameter of the shroud 26.

[0032]FIGS. 3 and 4 show a wind power installation 38 comprising a
streamlined support body 40 that supports a plurality of wind turbines
10. As can be seen in FIG. 3, the longitudinal cross section of the
support body 40 is substantially drop-shaped. The support body 40
comprises a rounded nose body 42 normally facing into the direction of
the wind during operation of the wind power installation 38 and a tail
body 44 normally facing away from the direction of the wind during
operation of the wind power installation 38. The support body 40 is
rotationally symmetrical about a longitudinal axis 46, herein referred to
as the support body axis.

[0033]The nose body 42 has substantially has the shape of a hemiellipsoid,
such as e.g. a hemisphere, rotationally symmetrical about the support
body axis 46. The plurality of wind turbines 10 are arranged
circumferentially around the support body 40 in a plane 48 of greatest
diameter of the support body 40, this plane 48 being perpendicular to the
support body axis 46. The turbines are arranged so that their axes are
substantially parallel with the support body axis 46.

[0034]The tail body 44 connects substantially flush to the nose body 42 at
the plane 48. In downwind direction, the tail body 44 tapers to the
support body axis in such a way that in the longitudinal cross section
the contour of the tail body follows the course of a parabola given by:

d ' ( x ) D SB = 1 - x ' 2 L TB 2 , ##EQU00005##

where DSB is the diameter of the support body 40 at the plane 48,
LTB the length of the tail body 44, x' the coordinate on the support
body axis 46 and d'(x) the diameter of the tail body 44 for the
coordinate x'.

[0035]The length LNB of the nose body 42 in the direction of the
support body axis 46 lies in the range from 0.4 to 0.6 times the diameter
DSB, i.e. 0.4DSB≦LNB≦0.6DSB, more
preferably in the range from 0.4 to 0.5 times this diameter DSB,
i.e. 0.4DSB≦LNB≦0.5DSB. The length LTB
of the tail body 44 lies in the range from 1 to 2 times the diameter
DSB, i.e. DSB≦LTB≦2DSB. The diameter
DS of the wind turbines 10 lies in the range from 0.4 to 0.6 times
the diameter DSB of the support body 40, i.e.
0.4DSB≦DS≦0.6DSB.

[0036]During operation of the wind power installation 38, the wind blows
from the side of the nose body 42, which directs the incoming wind away
from the support body axis 46 towards the turbines 10 arranged in a
circle around the support body 40 in the plane 48, in which the diameter
of the support body 40 is largest. The reduction of available cross
section causes the speed of the airflow to increase along the nose body
42. The speed reaches a maximum at the plane 48. Even at low wind speed,
the speed of the airflow at the turbines may thus be high enough to start
operation of the wind power installation.

[0037]To enable orientation of the wind power installation 38 into the
wind, the support body 40 is rotatably mounted with respect to a vertical
axis 50. This axis 50 preferably intersects with the nose body 42 or with
a part of the tail body 44 that is close to the nose body. In this case,
the wind power installation can be oriented by the forces of the wind. If
the support body axis 46 is not aligned with the direction of the wind,
the forces of the wind will create a moment on the support body 40 that
turns the wind power installation 38 with the nose body 42 into the wind.

[0038]FIGS. 5, 6, 7a and 7b show another type of a wind power installation
52. The wind power installation 52 comprises a series of mutually similar
wind power installation modules 56, arranged one above the other along a
vertical axis 54 to form a tower.

[0039]Each wind power installation module 56 has support body with a
substantially drop-shaped horizontal cross section, substantially
vertical outer walls 58 and is symmetrical with respect to a vertical
longitudinal plane 60. Each module 56 has a nose body 62 that normally
faces into the wind during operation of the wind power installation 52
and a tail body 64 that normally faces away from the wind during
operation of the wind power installation 52. The nose body has a
substantially hemielliptical horizontal cross section, whereas the tail
body tapers in downwind direction to the plane 60. Each module 56 further
comprises, arranged on both sides thereof, with respect to the plane 60,
wind turbines 10, whose turbine axes are substantially parallel to the
plane 60 and horizontal. The turbines 10 are arranged on the support
bodies where width thereof perpendicular to the plane 60 is maximum.

[0040]The length LNB' of the nose body 62 lies in the range from 0.4
to 0.6 times the width DSB' of the modules, i.e.
0.4DSB'≦LNB'≦0.6DSB', more preferably in the
range from 0.4 to 0.5 times this width DSB', i.e.
0.4DSB'≦LNB'≦0.5DSB'. The length LTB'
of the tail body 64 lies in the range from 1 to 2 times the width
DSB', i.e. DSB'≦LTB'≦2DSB'. The
diameter DS of the wind turbines 10 lies in the range from 0.4 to
0.6 times the width DSB', i.e.
0.4DSB'≦DS≦0.6DSB'.

[0041]During operation of the wind power installation 52, the wind blows
from the side of the nose bodies 62 of the individual modules 56, which
directs the incoming wind away from the respective plane 60 towards the
turbines 10 arranged laterally on the modules 56 with respect to the
direction of the wind. The reduction of available cross section causes
the speed of the airflow to increase along the nose bodies 62. The speed
reaches a maximum at the planes 60. Even at low wind speed, the speed of
the airflow at the turbines 10 may thus be high enough to start operation
of the wind power installation 62.

[0042]As the support body 52 is rotatably mounted with respect to the
vertical axis 54, the wind power installation 52 may orient itself into
the wind. For each module 56, the axis 54 preferably intersects with the
nose body 62 or with a part of the tail body 64 that is close to the nose
body 62. In this case, the modules 56 can be oriented by the forces of
the wind. Preferably, the modules 56 can rotate about the axis 54
independently from each other to enable optimal orientation in case of
the wind blowing from different directions at different heights from
ground. One can also limit the angular motion of neighbouring modules 56
to a certain angle.

[0043]FIGS. 8, 9, 10a and 10b show further embodiments of a wind power
installation. The wind power installation shown in FIGS. 8 and 9
comprises a wind power installation module 66 of substantially
drop-shaped horizontal cross section. The module 66 is substantially
symmetrical with respect to a vertical plane 68 extending in the
longitudinal direction of the module 66. The module 66 comprises an
immobile rounded nose body 70 that is rotationally symmetrical with
respect to a vertical axis and a tail body 72 that is mounted rotatably
about this vertical axis. The tail body 72, which, during operation,
extends downwind of the nose body 70, carries a plurality of wind
turbines 10 arranged in a semi-circular configuration in a vertical plane
74 perpendicular to the plane 68. The tail body 72 tapers in downwind
direction to a point so that contour of the tail body follows a parabolic
course. In a transversal cross section, the contour of the tail body is
substantially semi-circular.

[0044]During operation, the tail body 72 orients itself downwind under the
action of the forces of the wind, so that the turbines 10 become aligned
with the wind direction. The nose body 70 remains immobile while the tail
body 72 may pivot about the axis of symmetry of the nose body 70.

[0045]The horizontal diameter of the nose body 70 substantially
corresponds to the lateral diameter of the tail body 72. Indeed, the tail
body 72 is substantially flush with the nose body 70. The length
LTB'' of the tail body 72 lies in the range from 1 to 2 times the
width DTB'', i.e. DTB''≦LTB''≦2DTB''.
The diameter DS of the wind turbines 10 lies in the range from 0.4
to 0.6 times the width DTB'', i.e.
0.4DTB''≦DS≦0.6DTB''.

[0046]The wind power installation shown in FIGS. 10a and 10b comprises a
module 75 with a support body including a toecap-shaped nose body 76 and
a tail body 78 arranged substantially flush with one another. The support
body 76, 78 is symmetrical with respect to a vertical longitudinal plane
80. A plurality of wind turbines 10 are arranged in a half-circle around
the support body 76, 78 in the plane of greatest diameter of the support
body 76, 78, this plane being perpendicular to the vertical longitudinal
plane 80. The turbines are arranged so that their axes are substantially
perpendicular to the plane of greatest diameter. The outer appearance of
the present wind power installation is essentially that of the upper half
of the wind power installation 38 discussed with respect to FIGS. 3 and
4.

[0047]The module 75 is preferably rotatably mounted about an axis 82. It
should also be noted that the module 75 can be arranged as a terminal
module on top of a series of modules 56, as shown in FIGS. 7a and 7b.